The present invention relates generally to a power transmission for a working vehicle, such as, for example, a fork-lift car or the like. More specifically, the invention relates to a hydraulic pressure control system for the power transmission of the working vehicle, which system can shift between a forward and reverse drive in respective first and second gear positions with a single shift lever.
In the conventional working vehicle transmission, it has been required to incorporate two shift levers for switching between forward and reverse drive and for shifting the gear position. Since the working vehicle is required to frequently switch between forward and reverse drive, it is quite complicate to operate two shift levers for switching driving direction and shifting gear position. Further, the clutch of the working vehicle is thus frequently operated in switching the driving direction and shifting the gear position. Upon being operated from a disconnected position to a connected position, a hydraulic pressure is rapidly applied to the clutch thus preventing a moderate connection of the clutch. This tends to degrade drivability of the working vehicle.